Key takeaways:

• Women who had complications during their first pregnancy and did not get pregnant again had the highest risk.
• Women whose first pregnancy had complications but other pregnancies did not had the lowest risk.

The risk for premature death from CVD occurring from one or more complicated pregnancies may widely vary, new research in European Heart Journal shows.

“Cardiovascular disease in women is underrecognized and undertreated and, as such, pregnancy complications have been proposed as a way to identify at-risk women,” Aditi Singh, a PhD candidate at University of Bergen in Norway, said in a press release. “Our earlier work found that a woman’s risk of premature cardiovascular mortality increases with the number of complicated pregnancies. However, many studies and guidelines still only ask whether a woman has ever had a complication.”

Data derived from Singh A, et al. Eur Heart J. 2026;doi:10.1093/eurheartj/ehag564.

Recent research has suggested that higher psychosocial stress occurring during a pregnancy complication is linked to a greater risk for higher diastolic BP years after the pregnancy.

In the current study, Singh and colleagues analyzed 1967 to 2020 data from the Medical Birth Registry of Norway and Norwegian Cause of Death Registry to determine the risk for CVD death before age 70 years among 1,001,409 women with pregnancy histories.

Complications were assessed by lifetime occurrence, the sequence of occurrence (whether in a first or second pregnancy), recurrence and by type, which included gestational hypertension, preeclampsia, preterm delivery, perinatal loss, placental abruption and small for gestational age. The risks for premature CVD mortality were compared with women who had two or more uncomplicated pregnancies.

The researchers reported that women with a complication in their only pregnancy had the greatest increased risk [adjusted HR (aHR) = 3.3; 95% CI, 2.97-3.66] followed by those with a complication in both their first and second pregnancy (aHR = 2.41; 95% CI, 2.16-2.69).

“This is something often missed in studies that focus on a single pregnancy complication at a time,” Singh said in the release.

Moderate risks were seen among women with complications in later pregnancies only (aHR = 1.65; 95% CI, 1.5-1.81) and those whose only pregnancy was uncomplicated (aHR = 1.83; 95% CI, 1.69-1.97).

The lowest risk was among women with a complicated first pregnancy but no complications in further pregnancies (aHR = 1.39; 95% CI, 1.27-1.53), which “may reflect sufficient physiological adaptation following the previous pregnancy, or that these women benefited from medical and lifestyle interventions or closer clinical surveillance,” Singh and colleagues wrote.

When Singh and colleagues grouped women based on whether they ever had a pregnancy complication, there was a 1.73 times (95% CI, 1.64-1.84) higher risk.

Risks by the type of complication, they reported, were similar.

In the release, Singh said that they could not determine causality due to the analysis’ observational design.

Potential contributors behind the associations, Singh and colleagues wrote, are still not fully understood but “are thought to arise from placental dysfunction, driven by multiple factors including traditional CVD risk factors, genetic predisposition and fetal-maternal genomic interactions.”

“Regardless of the underlying mechanism, a woman’s pregnancy history still carries valuable information about her future risk, and that is something we can act on now, while further research works out exactly why these patterns exist,” Singh said in the release. “Identifying and following up these women is an important area for future work.”